Respectfully disagree. We're a mongrel, Constitutional nation with an undercurrent white-blood-cell English Common Law tradition. We have adapted to and accommodated immigrants in the past, and, if we can pare down the Public Sector weeds that choke our ideals, our Shining City on the Hill will flourish with the creativity, business, and ideals of the "wretched refuse" who will dare to expatriate and identify as "Hell Yes" Americans.
To become parochial at this point, what with the world's rising economic tide (courtesy mostly of Uncle Sam), regardless of political correctness, is self-immolating, IMHO.
We’re out of room and resources.
Let them all move in with you.
Then tell me how wonderful it is.